Comments by Kip Hansen — 8 September 2024
There has been a lot of attention paid to this year’s Hurricane Season in the weather media. We even had one re-post here at WUWT — Mysteries Surrounding The 2024 Atlantic Hurricane Season. CO2 Definitely Not the Driving Factor – from NoTricksZone which itself is a re-post translated from KlimaNachrichten. Not bad, but, to me, not really satisfying – after all, no one could possibly think that the slowness of a single hurricane season could be really driven by changes in CO2 concentrations in the atmosphere.
A sampling from the press, in no particular order:
“Lately, there’s also been chatter of very warm upper levels in the troposphere (at around 50,000 or 60,000 feet) – a byproduct of global warming – that could be making the Atlantic more stable than normal and capping thunderstorm growth despite record-warm sea surface temperatures.”
—
“The Atlantic Ocean is near record warm, and a favorable La Niña climate cycle is developing in the tropical Pacific Ocean. Yet at what is normally the peak of hurricane season, the ocean basin has stubbornly stayed in a deep slumber.”
—
“This hurricane season is confounding experts and defying forecasts. What the heck is going on?”
—
“Hurricane forecasters expect below-normal cyclone activity through September’s season peak….The period of tropical activity from Aug. 12 through Sept. 3 has marked the quietest period in tropical weather development in 56 years. CSU said through Sept. 16, the basin favors either below or near-normal activity with only a 10% chance of above-normal formation.”
And, finally, actually quoting someone who might have a professionally informed opinion:
“If you had told me a month ago that nothing would (develop) after Ernesto I wouldn’t have believed you,” said Phil Klotzbach, a hurricane expert and research scientist at Colorado State University. “It’s really surprising.” “Hurricane forecasters, including Klotzbach, were predicting the calendar flip from August to September would revive the season. Many widely used forecast models signaled the same thing. It didn’t pan out.”
We all saw the headlines earlier this year:
NOAA predicts above-normal 2024 Atlantic hurricane season — La Nina and warmer-than-average ocean temperatures are major drivers of tropical activity (May 23, 2024)
—
“Super-charged Atlantic hurricane season poised for intense activity — The 2024 Atlantic hurricane season is likely to be much worse than last year with 20 to 25 named storms predicted, and experts warn now is the time to prepare before the onslaught of storms and hurricanes begins.”
And then, later in the year, just a month ago:
Highly active hurricane season likely to continue in the Atlantic — Near-record sea surface temperatures and the possibility of La Nina are key factors (August 8, 2024)
That last NOAA press release includes this magnificent night-time satellite image of Hurricane Beryl as it approaches the coast of Texas:
[The full high-resolution image is well worth downloading here ]
Phil Klotzbach at CSU even issued a new forecast on August 6th still predicting an above-average season:
Most readers will know already that the season has thankfully under-performed:
And there we sit, still today on the 8th of September with the Atlantic Tropical Weather outlook, for the next 7 days:
The orange area represents a weather phenomenon where “a tropical depression could form during the early or middle part of next week while the system moves slowly northwestward to northward over the southwestern Gulf of Mexico.” So, not yet even a tropical depression. The yellow area has this: “Some slow development of this system is possible while the disturbance meanders through the early part of next week, then begins to move west-northwestward across the central tropical Atlantic during the middle to latter part of next week.”
And what might be forming? A Tropical Depression:
“Cyclones are characterized by a circular wind pattern or circulation.
Meteorologists identify the growth phase of hurricanes into three categories of development:
Tropical Depression — wind speeds less than 36 mph
Tropical Storm — wind speeds between 36 mph and 74 mph
Hurricane — wind speeds greater than 74 mph” [ source ]
So, to work its way up to being a hurricane, an area of low pressure with thunderstorms must first produce a circular wind flow with maximum sustained winds below 39 mph. Without the circular wind flow, winds of just below speed would be called a ‘near gale’ – or “A gale is a strong, sustained wind with wind speeds between 39 mph and 54 mph. The word is typically used as a descriptor for maritime weather.”
Note: I have sailed in a full gale, once, accidentally, and I did not like it.
The Seven-Day Outlook means that we will pass the historical peak day of Atlantic hurricane activity (below) without adding to the tally issued on 1 September (above).
From the 10th September, hurricane activity historically begins to slow down rather sharply by the 1st of October. After the 1st of October, probability of a hurricane drops by 40 to 50% compared to the peak. By the 1st of November, the season is pretty much over but officially ends on the 30th.
If I were still in the Virgin Islands (US or UK), I’d be feeling pretty confident and not running to Salinas, PR, which is the nearest dependably safe hurricane hole. The advantage of Salinas is that it is downwind and a quick easy sail, less than 24 hours, much of which can be accomplished overnight, even being chased by a storm arriving from the east.
Does any of this mean that the islands, the Yucatan, the Gulf Coast, both Florida coasts, the U.S. East Coast or the Bahamas can relax and think they dodged the hurricane bullet for the season? Absolutely not.
As NOAA keeps reminding us, it only takes one hurricane hitting your area to make a disaster.
The questions being asked in the Weather/Climate press are:
What does the obvious hurricane prediction failure mean?
Have we really gotten it that wrong?
Is there still a chance that the season will heat up and make up lost ground?
How did we/they get it so wrong?
Is there something fundamentally wrong with our models?
Those are all good questions and there have been a lot answers and a lot of excuses.
Many readers here are quite familiar with hurricane science and I’d like to read their opinions in the comments.
Here’s my take:
The basic cognitive error that I have identified is a confusion between:
1. Favorable conditions and indicators, learned from the experience of past seasons along with hypotheses about hurricane genesis
and
2. Cause
Hurricane predictions are naturally, quite correctly, made based on the historical past – identifying conditions that seem to have resulted in more hurricanes – and the statistical historical results (such as the Peak Season graphic) These are then coupled with hypothetical causes – things we think ought to cause more hurricanes – to come up with a guess – a prediction – of how activity the coming season will be.
That is a perfectly proper way to make these predictions. Not a piece out of place…..
Except…..
Statistics about the past are not causes.
Hypotheses about hurricane causation (or hurricane genesis) are not causes.
But, but , but….yes, I know. I suspect you are right, if those are not causes – meaning that looking at those non-causes might lead us astray in our prediction – then….
What does cause hurricanes?
Good question! Go to the top of the class.
Can I get an answer? Well, gee, I asked the Windows Copilot and it gave a sort of sciencey* non-answer that contained no causes, only favorable conditions and hypotheses about hurricane genesis.
* – “Appearing scientific without actually being so” [ source ]
We know the favorable conditions, we know the unfavorable conditions, we have some idea of the atmospheric mechanics involved (low pressure, circular wind patterns, etc).
If we knew the true causes, we would just need to look and see if the causes existed (or were likely to exist) and make a prediction.
Oddly, in 1963, David Fultz may have peeked at the answer in his rotating dishpan experiments at Chicago. [ here and here ] Edward Lorenz’s toy climate model, L96, could churn out the underlying chaotic genesis of hurricanes. In both cases, the causes are themselves related to topics in Chaos Theory studies.
If that is true – and I am not drawing a line in the sand here – then hurricane genesis is – buried under all the historic statistics, favorable conditions and hypotheses – basically unpredictable before the fact.
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Author’s Comment:
Don’t get me wrong, we can comfortably predict that there will be a hurricane season and it will have tropical cyclones and some of them will develop into hurricanes. But we can’t predict, for the next hurricane season or even the remainder of this hurricane season how many, precisely where or when, nor can we predict where those hurricanes that develop will go.
I am betting that there are conflicting opinions out there and I’d like to read them.
I don’t usually include graphics in this section, but was taken with this one:
We still might get some hurricanes after all – there have been more than a few (732) cyclones recorded in Septembers past.
Thanks for reading.
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